Electromechanical injection apparatus for medical and veterinary use actuated by a trigger

Abstract

An electromechanical injection device for medical and veterinary use comprises a frame (1) having the shape of a pistol provided with a stock (2) and bearing a movable carriage (3) that supports a removable syringe (4) having a needle (5) and a piston (6). A first motor (7) actuates a pusher (8) which acts against the piston (6) of the syringe (4). A cradle (9) is carried by the frame (1) and supports the syringe (4) on the movable carriage (3). A second motor (12) actuates the movable carriage (3). The forward portion of the frame has a stabilizing sight (10) for application to the skin which guides and predetermines the degree of penetration of the needle (5). An adjustment wheel (11) permits adjusting the position of the sight (10) to adjust the depth of penetration of the needle (5). A trigger (18) actuates the motors (7, 12). The second motor (12 ) is fixed to the frame (1) and has a rotatable axle (30) and a first cam (29) on that axle. The second motor (12) drives, via that axle (30) and the first cam (29), the movable carriage (3) in movement lengthwise of the frame (1). There is a second cam (26) on the trigger (18). The first and second cams (29, 26) coact with each other according to the translated position of the trigger (18) to control advancement of the piston (6).

What is claimed is: 
     
       1. In an electromechanical injection device for medical and veterinary use comprising a frame (1) having the shape of a pistol provided with a stock and along a longitudinal axis of said frame (2) and bearing a movable carriage (3) that supports a removable syringe (4) having a needle (5) and a piston (6), a first motor (7) actuating a pusher (8) which acts against the piston (6) of the syringe (4), a cradle (9) carried by the frame (1) and supporting the syringe (4) on the movable carriage (3), a second motor (12) actuating the movable carriage (3), the forward portion of the frame having a stabilizing sight (10) for application to the skin which guides and predetermines the degree of penetration of the needle (5), an adjustment wheel (11) which permits adjusting the position of the sight (10) to adjust the depth of penetration of the needle (5), and a trigger (18) to actuate said motors (7, 12); the improvement wherein said second motor (12) is fixed to the frame (1) and has a rotatable axle (30), a first cam (29) on said axle, said second motor (12) driving, via said axle (30) and said first cam (29) said movable carriage (3) in movement along said longitudinal axis of said frame (1), a second cam (26) on said trigger (18), said first and second cams (29, 26) coacting with each other according to the translated position of the trigger (18) to control advancement of said piston (6). 
     
     
       2. Device according to claim 1, wherein the trigger (18) is both rotatable and axially displaceable, and means (23, 24) in one rotated position of the trigger to prevent axial movement of the trigger. 
     
     
       3. Device as claimed in claim 1, wherein said first cam (29) is adapted to transform rotational movement into translatory movement and is in the form of a ring surrounding the axle (30) of the second motor (12) and has at least one helicoidal groove (35, 36) in which rids a lug (37) fixed to the axle (30) and has two lateral ears (32, 33) and is adapted to come into abutment against a manipulating tongue (31) of the movable carriage (3) to advance the carriage (3), said ears (32, 33) coacting with a positioning finger (34) on said second cam (26) to control the positioning of the carriage (3). 
     
     
       4. Device as claimed in claim 1, and a return spring (41) for urging said carriage rearwardly. 
     
     
       5. Device according to claim 1, wherein said trigger (18) is axially movable within said frame (1) and has a lug (25) which coacts with said second cam (26), said second cam (26) comprising a ring having at least one helicoidal groove (35, 36) in which said lug (25) is disposed. 
     
     
       6. Device according to claim 5, wherein said second cam (26) has a positioning finger (34) thereon which is adapted in one position to displace the first cam (29) so as to cause the first cam to advance the carriage (3) and in another position to act against lateral ears (32, 33) on the first cam to rotate the first cam to return the device to a position for a new cycle of operation.